Volume control of manual resuscitation bags is an important feature not presently found on commercially available manual resuscitation equipment. Volume control and adjustment is especially important, and may be critical, for resuscitating infants, particularly neonatal care patients. Typical infant and neonatal resuscitation bags have a volume capacity of about 100 ml. Yet for very small patients with such limited lung capacity, it is desirable to limit the volume delivered to the infant or prenatal patient to less than 100 ml, e.g., between about 10 ml and about 60 ml or between about 20 ml and about 80 ml per bag compression. It is to such a volume controllable manual resuscitation bag assembly that the present invention is directed.